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The influence of classroom environment on high school students' mathematics anxiety and attitudesTaylor, Bret Allen January 2004 (has links)
The purpose of this research was to examine the possible associations between the perceived classroom environment of high school students, the level of mathematics anxiety that they possess, and their attitudes towards mathematics. This marks the first time that these three fields of research have been simultaneously combined. Data were gathered from 745 high school mathematics students in 34 classes in high schools in the Southern California area using three instruments: the What is Happening In this Class? (WIHIC) learning environment survey created by Fraser, McRobbie, and Fisher (1996), an updated version of Plake and Parker's (1982) Revised Mathematics Anxiety Ratings Scale WRS), and a mathematics version of selected scales from Fraser's (1981) Test of Science-Related Attitudes (TOSRA). This revised attitude instrument was called the Test of Mathematics-Related Attitudes (TOMRA). Using statistical methods, the three instruments were checked for internal consistency reliability, factor structure, and discriminant validity. The RMARS and WIHIC were both found to exhibit good reliability and factorial validity in mathematics classrooms in Southern California, while the TOMRA yielded two scales of the four a priori scales, Enjoyment of Mathematics Lessons and Normality of Mathematicians, which met reliability and factorial validity standards. Within-class gender differences were analysed using paired t-tests combined with a modified Bonferroni procedure and effect sizes. Between- student gender difference were investigated using MANOVA. Simple correlation and multiple regression analyses were performed to identify possible associations between the learning environment and anxiety/attitudes scales. Qualitative data were collected from interviews and inductive analysis was performed in order to refute or corroborate the quantitative findings. / Significant within-class gender differences were found in four areas of the learning environment (Student Cohesiveness, Task Orientation, Cooperation, and Equity), but no gender differences in attitudes were found. All four learning environment areas were perceived in a more favourable light by females than by males. Individual gender differences were similar, with a significant difference also being found in Teacher Support, as well as both types of mathematics anxiety, namely, Learning Mathematics Anxiety and Mathematics Evaluation Anxiety. In order to carefully identify the relationships between the classroom learning environment and mathematics anxiety, analyses were conducted for both factors of mathematics anxiety. While no association between the learning environment and Mathematics Evaluation Anxiety was found, there were significant associations between Learning Mathematics Anxiety and three areas of the learning environment: Student Cohesiveness, Task Orientation, and Investigation. Significant associations between the Normality of Mathematicians attitude scale and the learning environment scales Equity and Involvement were identified, while three areas of the learning environment (Investigation, Task Orientation, and Cooperation) had a significant relationship with Enjoyment of Mathematics Lessons. Qualitative data analyses confirmed relationships between anxiety, attitudes, and classroom learning environments. The data also suggest that the structure of the mathematical content is linked with the level of anxiety that high school students feel.
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The measurement of the pressure distribution over the wing of an aircraft in flightMcCarty, Matthew, Aerospace, Civil & Mechanical Engineering, Australian Defence Force Academy, UNSW January 2008 (has links)
A measurement system has been developed for use on a light aircraft to measure the pressure distribution over the wing surfaces. The measurement system was developed as a low-cost alternative to existing advanced measurement systems. The system consisted of low profile, low cost pressure sensors that interfaced digitally with microcontrollers for data acquisition. The pressure sensors and microcontrollers were developed into self-contained sensor modules with all electronic components mounted on flexible circuit board that formed the base of the modules. Two types of module were developed; a module with a single pressure sensor and a module with a row of seven pressure sensors at fifteen millimetre spacing. The total cost of the sensor modules was approximately ninety dollars for a single sensor module and one hundred and forty dollars for the seven sensor module. Studies were carried out using numerical methods to predict the pressure distribution over a NACA2412 airfoil. The numerical studies were used to evaluate the effect of adding the sensor modules to the wing, and the effect of the sensor distribution on measured force coefficients. Numerical predictions were made using the XFOIL software package. This software was validated using the Hess-Smith inviscid panel method. Flight testing was carried out with the pressure distribution measurement system to confirm the operation of the system and to make preliminary measurements. The flight testing focused on the measurement of steady state pressure distributions for comparison with the numerical predictions. Good agreement was found between the measured pressure distributions and the XFOIL predictions. Integration of the pressure distributions enabled comparison of normal force, lift force and quarter chord moment coefficients. The measured force coefficients showed the expected trends with angle of attack although it was found that the limited number of sensor modules used caused large error in the quarter chord moment coefficient compared to the numerical predictions.
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Depression in palliative care patients in Australia: identification and assessmentCrawford, Gregory Brian, gregory.crawford@adelaide.edu.au January 2008 (has links)
Depression is poorly recognised, under-assessed and under-treated in patients receiving palliative care for a life-limiting illness. There are barriers to assessment and diagnosis, and limited access to specialist clinicians who might assist in these complex assessments and who could provide options for treatment.
The three studies presented, using different research methodologies, and using both qualitative and quantitative analysis, seek to clarify these issues and to provide some solutions. A questionnaire was sent to all Palliative Care Services (PCS) in Australia. Questions included what part specialist psychological clinicians played in multi-disciplinary team meetings and in the treatment or coordination of patient care. Very few PCS used a valid screening instrument for psychological distress and very few had regular support from a psychiatrist or psychologist. Many did not have access to social work support.
There are two competing issues with regard to recognising and assessing depression in palliative populations. A rapid reliable screen that points to a likely problem would be useful, but also there is a need to understand something of the patient experience of depression.
In the second study, the one- and two-item screening instruments widely used in palliative care are examined and limitations that have been found in other settings are confirmed. A new novel screening tool is developed from this data and tested empirically. This algorithm is short, has good psychometric properties and is validated for an Australian palliative care population. Depending on the response pattern it is possible to identify that a particular patient has significant symptoms of depression by asking between one and four questions. Professional carer and patient acceptability of the questions is high.
The understanding of the experience and symptom profile of depression in Australian palliative care patients is addressed in the third study. Patients and family carers were recruited prospectively from palliative care and oncology ambulatory clinics of two teaching hospitals in an Australian capital city. The Geriatric Depression Scale (GDS) was administered to the patient and the Collateral Source version of this instrument was asked of the carer. A subset of this sample completed the measures twice. The results using this 30-item scale were then compared with all the known previously published short versions of this scale. Two short forms met as many psychometric criteria as the longer forms. None of the versions of the GDS showed sufficiently high correlations between carer-completed and patient-completed forms. The frequency of symptoms was also assessed. Patients more frequently reported fatigue and anhedonia than depressed affect.
Despite many screening instruments being available for depression, their use is limited in Palliative Care Services. Although these studies have validated several options for Australian palliative care patients, the issues behind the low uptake rates for screening have not been resolved. The final chapter of this thesis constructs known and potential barriers into a logical structure and then offers some solutions to improve access to mental health professionals by considering service models and applying this theory to the problem of depression and its assessment in palliative care populations.
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Flute acoustics: measurement, modelling and designDickens, Paul, Physics, Faculty of Science, UNSW January 2007 (has links)
A well-made flute is always a compromise and the job of flute makers is to achieve a musically and aesthetically satisfying compromise; a task that involves much trial and-error. The practical aim of this thesis is to develop a mathematical model of the flute and a computer program that assists in the flute design process. Many musical qualities of a woodwind instrument may be calculated from the acoustic impedance spectrum of the instrument. A technique for fast and accurate measurement of this quantity is developed. The technique is based on the multiple-microphone technique, and uses resonance-free impedance loads to calibrate the system and spectral shaping to improve the precision at impedance extrema. The impedance spectra of the flute and clarinet are measured over a wide range of fingerings, yielding a comprehensive and accurate database. The impedance properties of single finger holes are measured using a related technique, and fitformulae are derived for the length corrections of closed finger holes for a typical range of hole sizes and lengths. The bore surface of wooden instruments can change over time with playing and this can affect the acoustic impedance, and therefore the playing quality. Such changes in acoustic impedance are explored using wooden test pipes. To account for the effect of a typical player on flute tuning, an empirical correction is determined from the measured tuning of both modern and classical flutes as played by several professional and semi-professional players. By combining the measured impedance database with the player effects and various results in the literature a mathematical model of the input impedance of flutes is developed and implemented in command-line programs written in the software language C. A user-friendly graphical interface is created using the flute impedance model for the purposes of flute acoustical design and analysis. The program calculates the tuning and other acoustical properties for any given geometry. The program is applied to a modern flute and a classical flute. The capabilities and limitations of the software are thereby illustrated and possible contributions of the program to contemporary flute design are explored.
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Comparison of three nickel-titanium instruments and the step-down technique for preparing curved root canalsWei, Xi. January 2000 (has links)
Thesis (M.D.S.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 119-130) Also available in print.
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Development of high performance implantable cardioverter defibrillator based statistical analysis of electrocardiographyKwan, Siu-ki. January 2007 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.
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La dynamique des instruments de gestion : propositions pour un cadre d'analyseOiry, Ewan 26 October 2009 (has links) (PDF)
La problématique de cette HDR est ainsi : l'analyse articulée de la conception et des usages des instruments de gestion permet-elle d'en comprendre la dynamique ? Pour répondre à cette question, mes recherches ont progressé selon trois temps complémentaires. Tout d'abord, à partir d'une interrogation sur l'opposition entre qualification et compétence, j'ai analysé la manière dont les instruments de gestion se construisent. Cette première série de travaux m'a permis d'aboutir à la proposition théorique : les instruments de gestion sont des chaînes de traductions reliées par des rapports de prescription. Dans une seconde série de travaux, j'ai testé cette proposition théorique sur un instrument de rémunération des compétences et sur des référentiels de compétence. J'engage aujourd'hui une troisième série de travaux où j'utilise mes travaux sur la conception des instruments de gestion pour en analyser les usages. L'idée est ici que la connaissance de l'histoire de la construction d'un instrument, des acteurs qui y ont participé et des enjeux qu'elle a affrontés donne des clés de compréhension de la diversité des usages que l'on constate généralement pour un instrument de gestion.
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Small sample performances of two tests for overidentifying restrictionsTongur, Can January 2006 (has links)
<p>Two new specification tests for overidentifying restrictions proposed by Hahn and Hausman (2002:b) are here tested and compared to the classical Sargan test. Power properties are found to be very similar in overall performance, while Sargan generally has better size than the new tests. Also, size is distorted for one of the new tests, thus a tendency to reject prevails. In addition, sometimes severe bias is found which affects the tests’ performances, something that differs from earlier studies.</p>
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Monte Carlo MDA determination for waste drum sourcesBuchholz, Matthew A. 16 October 2001 (has links)
Past weapons production activities have resulted in mass quantities of trans-uranic
waste being buried in drums at several sites in the United States. In an effort to
relocate these waste drums to more permanent storage sites, Fluor Hanford has
begun characterizing their contents to ensure compliance with various shipping and
storage requirements. Non-destructive analysis techniques are regularly employed,
among them passive radiation detection using a Canberra Gamma-Energy-Analyzer
germanium detector vault. Necessary strict legal tolerances require strong quality
assurance. The detectors are frequently calibrated in the traditional method with
check sources, but it would be advantageous to have an estimate of system
minimum detectable activity (MDA). However, any estimate is complicated by the
fact that sources are distributed stochastically in the waste drums.
In this study, a method was developed to predict system detector efficiency for a
variety of detector configurations and drum fill materials and calculate MDA based
on these efficiencies. The various system designs were modeled in Monte Carlo
N-Particle Code, version 4b, to determine photopeak detection efficiency. An
external code written in C programming language was used to randomly assign
between one and 20 sources to volumetric regions of the waste drum. Twenty
simulations were performed for each design and drum fill material combination,
each time redefining the stochastically distributed source. This provided a
normally distributed spectrum of 20 efficiencies for each situation. From this,
mean and lower 95% confidence limit efficiencies were used to calculate MDA.
The patterns among the results were then compared with values predicted by the
MDA formula. Finally, an examination was made of the impact on the MDA of the
system's true design in the case of single or multiple detector failure.
The results indicate that this method of estimating minimum detectable activity,
although costly in computing time, provides results consistent with intuitive and
calculated expectations. Future work would allow easy calibration of the model to
measured efficiency results. Used in coordination with physical experiments, this
method may eventually prove useful in benchmarking system performance and
accurately ensuring reliable waste drum characterizations. / Graduation date: 2003
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Essays on the volatility of macroeconomic and financial time series /Yu, Wei-Choun. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 109-116).
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